BMR Calculator

Partner

Understand Your Body Better

Track your weight, body fat, muscle mass, and bone density with a smart Wi-Fi scale that syncs automatically to your health apps for a complete body analysis.

Shop Withings Smart Scales
We may earn a commission from qualifying purchases.

Related

TDEE Calculator Calorie Calculator Body Fat Calculator BMI Calculator

About BMR Calculator

The Basal Metabolic Rate (BMR) is the energy your body needs at rest to keep vital functions running (breathing, circulation, cell maintenance). This calculator uses the Mifflin–St Jeor equation, a widely recommended method for adults, and can also estimate TDEE (daily maintenance calories) by applying an activity multiplier.

How to use

  1. Enter age, sex, height, and weight (kg/lb, cm/in).
  2. Click Calculate to see your BMR, then multiply by your activity level for TDEE.
  3. Set goals: create a modest deficit for fat loss or a small surplus for muscle gain.

Tips & limits

  • BMR vs RMR: RMR is a very similar resting measure; differences are small for most users.
  • Body composition matters: More lean mass usually means a higher BMR.
  • Use trends (weight/measurements 2–3 weeks) to fine-tune calories in ±100–200 kcal steps.

FAQ

  • What is BMR?
    Basal Metabolic Rate is the calories your body needs at complete rest to sustain vital functions.
  • Which equation does this BMR Calculator use?
    Mifflin–St Jeor, commonly recommended for adults in nutrition research.
  • What’s the difference between BMR and TDEE?
    BMR is at rest; TDEE = BMR × activity factor (1.2–1.9) to include daily movement and training.
  • How accurate is a BMR calculation?
    It’s a researched estimate. Validate with real-world trends and adjust intake by ~100–200 kcal as needed.
  • Does muscle mass raise BMR?
    Yes—more lean mass generally increases resting energy needs.
  • How often should I recalculate?
    After notable weight changes (±2–3 kg), activity shifts, or every few weeks during a program.
  • How do I go from BMR to daily calories?
    Use TDEE = BMR × activity factor, then set a deficit/surplus to match your goal.

Disclaimer

The tools provided on this site are intended for educational and informational purposes only and are not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a qualified health provider with any questions you may have about a medical condition. If you think you may have a medical emergency, call your local emergency number immediately.

Equations are intended for adults and provide estimates that may not apply to children, pregnant or breastfeeding individuals, or certain medical conditions.

References